Prenatal Environmental Antibiotic Exposure and Autism Spectrum Disorder Symptoms in Children at 3 Years of Age: Findings from the Ma'anshan Birth Cohort Study.

Antibiotic exposure during pregnancy may affect the neurodevelopment of children, but biomonitoring-based population studies on this class of new pollutants are lacking. We conducted a prospective birth cohort study of 2860 mother-child pairs, measured the urinary concentrations of 41 antibiotics and their two metabolites over three trimesters, and assessed children's autism spectrum disorder (ASD) symptoms at 3 years of age. We examined the associations between prenatal antibiotic exposure and children's ASD symptoms. The least absolute shrinkage and selection operator regression screened for Tetracycline and Ofloxacin as important predictors of ASD symptoms. Modified Poisson regression models revealed that maternal Tetracycline exposure throughout pregnancy increased the risk of ASD symptoms (RR: 1.66, 95% CI: 1.14, 2.40). Maternal Tetracycline exposure during the first (RR: 1.74, 95% CI: 1.13, 2.68) and third trimesters (RR: 1.86, 95% CI: 1.16, 3.00) increased the risk of ASD symptoms in boys, and Ofloxacin exposure during the first trimester (RR: 1.47, 95% CI: 1.07, 2.02) increased the risk of ASD symptoms in girls. No dose-dependent relationships between prenatal antibiotic exposure and ASD symptoms were validated by restricted cubic splines. Prenatal exposure to Tetracycline and Ofloxacin may increase the risk of ASD symptoms in children, and the first and third trimesters might be the key windows.